– 19 – – 20 – – 21 – – 22 –
SECTION 7
DIAGRAMS
7-1. IC PIN FUNCTION DESCRIPTION
•LCD BOARD IC401 LC867124A-5M74 (SYSTEM CONTROLLER, LCD DRIVER)
Pin No. Pin Name I/O Description
1 SHOCK O C2 flag shock detection once danger signal output to the LC78626KE (IC502)
“L”: shock detection danger
2 PAUSE O Pause signal output to the LC78626KE (IC502) “H”: pause
3 WOK O D-RAM writing enable signal output to the LC78626KE (IC502) “H”: writing enable
4 BUZ O Buzzer sound drive signal output terminal
5 CORES O External reset signal output to the CD control signal counter (IC404) and LC78626KE (IC502)
“L”: reset
6 LMT I Sled limit-in detection switch (S603) input terminal
7 RES I System reset signal input from the reset signal generator (IC402) “L”: reset
For several hundreds msec. after the power supply rises, “L” is input, then it changes to “H”
8 XT1/P74 I Sub system clock input terminal (32.768 kHz)
9 XT2/P75 O Sub system clock output terminal (32.768 kHz)
10 VSS1 — Ground terminal
11 CF1 I Main system clock input terminal (3 MHz)
12 CF2 O Main system clock output terminal (3 MHz)
13 VDD1 — Power supply terminal (+2.8V)
14 KEY1 I Key input terminal (A/D input)
S402, S403, S421, S422, S424 (WORLD/LOCAL, D.S.T. SUMMER T., ESP, CD PLAY
MODE, CLOCK) keys input
15 KEY2 I Key input terminal (A/D input)
S711 to S715 (TUNE/SCAN TIME SET – ., ALARM TRACK/STATION, ALARM TIME,
ALARM MODE, BAND) keys input
16 KEY3 I Key input terminal (A/D input)
S706 to S710 (STATION zSELECT/zPRESET 1/2/3/4/5) keys input
17 KEY4 I Key input terminal (A/D input)
S701 to S705 (TUNE/SCAN TIME SET + >, SNOOZE SLEEP OFF/LIGHT, xOFF
ALARM RESET, RADIO SLEEP, CD u) keys input
18 OPEN I CD door open/close detection switch (S423) input terminal
19 AFC O AFC control signal output to the CXA1111N (IC1) when FM reception
20 REG I Input of monitor signal of constant-voltage power supply generated form CXA1111N (IC1)
(A/D input)
21 BATT I Battery voltage detection input terminal
22 EMPN I D-RAM low capacity alarm signal input from the LC78626KE (IC502) “L”: less capacity
23 CNTOK I Data connection point detect completion signal input from the LC78626KE (IC502)
“H”: detection completed (D-RAM writing starts)
24 OVR I D-RAM writing interruption signal input from the LC78626KE (IC502)
(RZP pulse signal input in case of overflow or shock)
25 DRF I DRF (focusing detection) signal input from the LA9251M (IC501)
26 WRQ I Subcode Q output standby input from the LC78626KE (IC502)
27 C2F I C2 flag signal input from the LC78626KE (IC502)
28 AC IN I Power failure detection input terminal “L”: power on, “H”: power failure
29 SHIFT O Shift clock output of the main system clock (3 MHz) “H” active
30 BEEP MUTE O Beep sound muting on/off control signal output terminal “L”: muting on
31 to 40 S4 to S13 O Segment drive signal output to the liquid crystal display (LCD401)
41 VDD3 — Power supply terminal (+2.8V)
42 VSS3 — Ground terminal
43 to 60 S14 to S31 O Segment drive signal output to the liquid crystal display (LCD401)
Pin No. Pin Name I/O Description
61 CE2 I Setting terminal for the model Not used
62 CE3 I Setting terminal for the model “L”: ICF-CD2000, “H”: ICF-CD2000S
63 J I Setting terminal for the model “H”: E, Singapore, Tourist model
64 to 67 COM0 to COM3 O Common drive signal output to the liquid crystal display (LCD401)
68 VSS2 — Ground terminal
69 VDD2 — Power supply terminal (+2.8V)
70 CD ON O Power on/off control signal output for the CD mechanism section “L”: power on
71 TU ON O Power on/off control signal output for the tuner section “L”: power on
72 A MUT O Audio line muting on/off control signal output terminal “L”: muting on
73 LED ON O LED drive signal output of the liquid crystal display (LCD401) back light (D405 to D408)
indicator
74 SL – O Sled servo drive signal output to the LA9251M (IC501)
75 SL + O Sled servo drive signal output to the LA9251M (IC501)
76 RCK O Serial data latch pulse signal output to the CD control signal counter (IC404)
77 RWC O At tuner mode : PLL serial data latch pulse signal output to the FM/AM PLL (IC3)
At CD mode : Reading/writing control signal output to the LC78626KE (IC502)
(shumitt output)
78 COIN I At tuner mode : PLL serial data input from the FM/AM PLL (IC3)
At CD mode : Command serial data input from the LC78626KE (IC502)
79 SQOUT O At tuner mode : PLL serial data output to the FM/AM PLL (IC3)
At CD mode : Subcode Q data output to the LC78626KE (IC502)
80 CQCK O At tuner mode : PLL serial data transfer clock signal output to the FM/AM PLL (IC3)
At CD mode : Subcode Q data reading clock signal output to the LC78626KE (IC502)
Focus bias Check
Condition:
• Hold the set in horizontal state.
Check Procedure:
1. Put the disc. (YEDS-18)
2. Set the equipment to service mode stop state. (See page 11)
3. Connect the oscilloscope to the test point TP (RF) on the MAIN
board.
4. Move the optical pick-up to the center by pressing the >
and .keys.
5. Press the [BAND] key. (Both tracking and sled are turned ON)
6. Check the oscilloscope waveform is as shown below.
A good eye pattern means that the diamond shape (◊) in the
center of the waveform can be clearly distinguished.
RF Signal ReferenceWaveform (Eye Pattern)
VOLT/DIV : 200 mV (With the 10:1 probe in use)
TIME/DIV : 500 ns
To watch the eye pattern, set the oscilloscope to AC range and
increasethe vertical sensitivity of the oscilloscope for easywatch-
ing.
7. Stop revolving of the disc motor by pressing the
[ OFF ALARM RESET] key.
8. After the completion of adjustment, reset service mode. (See
page 11)
Check Location: MAIN Board (See page 20)
RF level
0.9 to 1.3 Vp-p
oscilloscope
(AC range)
+
–
MAIN board
TP (RF)
TP (VC)
(See page 14)
x
Check Location:
– MAIN Board (Conductor Side) –
TP
(DV)
TP
(MDV)
TP
(OPDV)
TP
(+3V)
TP
(+3.4V)
TP
(TE)
TP
(VC)
TP
(RF)
TP
(GND)
TP
(POWER +B)
TP
(PRE VC) TP
(PRE +B)